Beam grid for roof or floor construction



Nov. 26, 1940. E. MAIER 2,222,981

BEAM GRID FOR ROOF OR FLOOR CONSTRUCTION Filed Sept. 2. 1938 Patented Nov. 26, 1940 orrics BEAM GRID FOR- ROOF OR FLOOR CONSTRUCTION Erwin Maier, Schafihausen, Switzerland, assignor Y to Stephan Szegii, Detroit, Mich.

Application September 2,

1938, Serial No. 228,158

In Switzerland January 14, 1938 6 Claims.

This invention relates to floor, roof and like structures of the kind wherein the beams are arranged in two intersecting sets to form a plane structural grid. Such a structure is, of course, subjected to bending moments only, and therefore all the beams and all their interconnected points (i. e., the nodes) must be bend-rigid in both directions.

The object of the present invention is to provide a more efiicient plane grid structure which, among other advantages, enables a sufiicient decrease of the said bending moments to be obtained without any consequential disadvantages, as for example uplift or too many beams in the corners.

For this purpose the present invention consists in a plane beam grid arranged in two intersecting sets wherein the length ratio of the beams meeting at the edge nodes nearest the boundary corners is 3 to 1.

According to one form of embodiment of the invention the grid structure may be such that no beams extend diagonally from the corners but only from edge to edge of the boundary, and furthermore that the said diagonally directed beams do not rest on the shortest beams of the intersecting set, but are only fixed to the ends of the same at the boundaries.

In this form of structure according to the invention the second shortest beam is fully fixed at the boundary, namely into the shortest beam and also into the edge beam respectively. In this manner the field is relieved of the load in a simple manner and a large number of beams intersecting at the corners, as well as the lifting effect thereat is avoided.

A further advantage of the invention consists in that the new arrangement forms a widemeshed grid with a small number of beams; for example there are in a square bay only 16 beam units needed between the nodes.

The grid according to the invention may also be cranked either once or alternately upwards and downwards along beam intersection points 40 located on lines parallel to a boundary, or to one set of grid beams or to both of the same, whereby the cranking may be efiected at each row of intersection points or between the same.

The invention is illustrated by way of example 50 in the accompanying drawing in which:

Fig. l is a plan view of-one form of embodiment of the invention,

Fig. 2 is a plan view of a second form of embodiment; and

55 Fig. 3 is a longitudinal section of Fig. 2'.

In said drawing, Fig. 1 shows a square grid comprising two series of intersecting beams diagonal to the boundary d. The second shortest beams 11 are exactly three times the length of the shortest beams b. Beams a and b intersect on 6 the nodes 0 which are located on the edges only of the boundary, the grid beams extending only from edge to edge and not passing through a corner of the bay.

Fig. 2 shows a rectangular grid also comprising 10 two series of intersecting beams diagonal to the boundary m. The second shortest beams e are exactly three times the length of the shortest beam f and in addition longer beams gr are provided parallel to the beams e. The shortest beams J and longest beams g intersect at nodes located only on the boundary m, the grid beams in this case also extending only from edge to edge.

The beams are cranked along lines which are parallel to a boundary or to one set of intersecting beams and which contain the nodes i and is but not necessarily cranked along every such line.

It is to be understood that the invention is not limited to the particular form of cranking illustrated but any method of cranking may be employed.

I claim:

1. A floor or roof structure comprising two series of intersecting beams diagonal to the boundaries thereof and forming a plane structural grid, the said beams being continuous between the boundaries, and wherein the length ratio of the beams meeting at the edge nodes on the shorter boundary nearest the boundary corners is 3 to 1.

2. A floor or roof structure comprising two series of intersecting beams diagonal to the boundaries thereof and forming a plane structural grid, the, said beams being continuous between the boundaries, and wherein the length ratio of the beams meeting at the edge nodes on the shorter boundary nearest the boundary corners is 3 to 1, the diagonal beams extending only from edge to edge of the boundary.

3. A floor or roof structure comprising two series of intersecting beams diagonal to the boundaries thereof and forming a structural grid, the said beams being continuous between the boundaries, and wherein the length ratio of the beams meeting at the edge nodes on the shorter boundary nearest the boundary corners is 3 to 1, said grid being cranked once along a line parallel to a boundary.

4. A floor or roof structure comprising two series of intersecting beams diagonal to the boundaries thereof and forming a structural grid, the said beams being continuous between the boundaries, and wherein the length ratio of the beams meeting at the edge nodes on the shorter boundary nearest the boundary corners is 3 to 1, said grid being cranked upwards and downwards along lines parallel to a boundary.

5. A floor or roof structure comprising two series of intersecting beams diagonal to the boundaries thereof and forming a structural grid, the said beams being continuous between the boundaries, and wherein the length ratio of the beams meeting at the edge nodes on the shorter boundary nearest the boundary corners is 3 to 1,

15 the diagonal grid beams extending only from edge to edge of the boundary, said grid being cranked once a line parallel to a boundary.

6. A floor or roof structure comprising two series of intersecting beams diagonal to the boundaries thereof and forming a structural grid, the said beams being continuous between the boundaries, and wherein the length ratio of the beams meeting at the edge nodes on the shorter boundary nearest the boundary corners is 3 to 1,

ERWIN MAIER. 

